Many computer monitors and mobile devices utilize edge-lit liquid crystal displays (LCDs), as a source of illumination as they are compact and lightweight. The structure of such typical edge-lit liquid crystal display 10 is shown in FIG. 1. As such, unpolarized light is produced by an edge light 20 that is provided by the display 10, whereby light 30 enters a waveguide or waveguide diffuser plate 40, which is typically formed from plastic or glass for example, which has a refractive index that is higher than the surrounding air. In addition, the display 10 also includes mirrors 50 to enable the reflection of light 30 out of the waveguide diffuser plate 40. The conventional display 10 also includes a plurality of other layers that are disposed upon the waveguide diffuser plate 40, including a base polarizer film 60, a bottom substrate layer 70, a liquid crystal material layer 80, a top substrate layer 90, and a top polarizer film 92.
Thus, during operation of the display 10, when the light 30 generated by the edge light 20 hits or strikes the interface between the waveguide 40 and the environmental or surrounding air with a small incident angle, the light 30 comes out of, or is emitted by, the waveguide diffuser plate 40. Alternatively, when light 30 hits the interface between the waveguide 40 and environmental or surrounding air with a large incident angle, the light 30 is totally reflected by the interface and continues to propagate within the waveguide diffuser plate 40 where the light is reflected by the mirrors 50 out of the waveguide diffuser plate 40. When the light 30 hits or strikes the air/waveguide diffuser plate 40 interface at another location with a small incident angle, the light 30 also comes out of, or is emitted from, the waveguide diffuser plate 40. Thus, light 30 that is produced by the edge light 20 is unpolarized, and generally spreads out and exits the waveguide diffuser plate 40. Specifically, such diffused light emitted by the waveguide 40 is identified by reference numeral 30 in FIG. 1. Next, the unpolarized light 30 that exits the waveguide diffuser plate 40 is passed through a polarizer film 60 or other polarization device. The polarizer film 60 operates, such that half of the unpolarized light 30 is linearly polarized (referred to by numeral 30A), and is permitted to pass out of the polarizer 60, while the other half of the unpolarized light 30 (i.e. unpolarized portion) is absorbed by the polarizer 60, and as such, it does not pass out of the polarizer 60. Therefore, in conventional display designs, such as that of display 10, which utilizes an edge light 20, half of the light 30 produced by the edge light 20 is wasted due to its absorption by the polarizer 60. As a result of the lost light intensity, the conventional display 10 produces a dimmed image, or requires the use of an edge light 20 that is larger and consumes more power to compensate for the reduction in light intensity due to the absorption of light 30 by the polarizer 60.
Therefore, there is a need for a polarizing waveguide plate of the present invention that is configured so that unpolarized light produced by an edge light, which propagates through the diffuser plate with one linear polarization (i.e. the first polarization) is scattered out of the waveguide and toward a liquid crystal panel display (LCD), while the light with a polarization to orthogonal to the first polarization (i.e. the second polarization) that is not scattered, or is weakly scattered, is converted, so as to be approximately linearly polarized with the light of the first polarization and reflected out of the waveguide plate and toward the LCD display. In addition, there is a need for a polarizing waveguide plate of the present invention that is configured to increase the light efficiency of edge-lit displays, such as LCD (liquid crystal display) devices. Furthermore, there is a need for a polarizing waveguide plate of the present invention that enhances the intensity of the light emitted from the waveguide.